Vapor-rectifier.



F1 CONRAD & K. A. SIMMON- VAPOR RECTIFIER.

APPLICATION HLED JULY H. 1914.

Patented Nov. 14, 1916.

2 SHEETS-SHEET l.

INVENTORS. FrunK Conrad. Karl A. Sammon.

ATTORNEY PETERS C0 Puma-Lima" wasuificmn, n. c.

F. CONRAD & K. A. SIMMON.

' VAPOR RECTIFIER.

APPLICATION FILED JULY 11.1914.

1 204,41. Patented Nov. 14, 1916'.

2 SHEETSSHEET 2- WITNESSES! INVENTORS. Frank Conrad.

ATTORNEY UNITED STATES PATENT OFFICE.

FRANK CONRAD, OF SWISSVALE, AND KARL A. SIMMON, OF WIIiKINSBURG, PENNsYL- VANIA, ASSIGNORS T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COM- PANY, A CORPORATION OF PENNSYLVANIA.

VAPOR-RECTIFIER.

Specification of Letters Patent.

Patented Nov. 14, 1916.

Application filed July 11, 1914. Serial No. 850,346.

To all whom it may concern:

Be it known that we, FRANK CONRAD, a citizen of the United States, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, and KARL A. SrMMoN, a citizenof the United States, and a resident of Vvilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Vapor-Rectifiers, of which the following is a specification. I I

Our invention relates to rectifying systems adapted to be employed in connection with the vehicles of electric railways, and it has for its object to provide a system of the character specified that will permit the use of a plurality of rectifiers, either singly or in multiple, together with means for control ling the speed of the .vehicle in a simple and economical manner.

Referring to the accompanying drawings, Figure 1 is a circuit diagram embodying my invention, and Fig. 2 is a schematic diagram of the circuit shown in Fig. 1.

One terminal of the primary winding 17 of a transformer 18 is connected to the current-supply wire 19 of an electric railway by means of a line switch 20 and a trolley 21. The other terminal of the primary winding 17 is connected to the ground, as shown at 22. The secondary winding 23 of the transformer 18 is provided with a plurality of taps 1, 2*, 3, etc., and each of these taps is connected to one terminal of a contact device 1, 2, 3, etc. The other terminals of contact devices 1 and 13 are strapped together and connected to the two upper terminals of a doublep0le, doublethrow switch 25. The other terminals of the contact devices 5 and 9 are connected to the center contacts, respectively, of the switch 25. The two lower terminals of the switch 25 are connected to a pair of bus-bars 30 and 31. In a like manner, a double-pole, double-throw switch 26 is connected to the contact devices 3, 7, 11, 15 and to bus-bars 29 and 31; a double-pole, double-throw switch 27 isconnected to contact devices 2, 6, 10 and 14 and to bus-bars 29 and 30;'and a double-pole, double-throw switch 28 is connected to contact devices 4, 8, 12, and 16 and to the bus-bars 30 and 31. The bus-bars 29, 30 and 31 are connected, respectively, to the three center contacts of a triple-pole, doubletively; the middle contacts of this switch are connected to the upper contact members of the switches 27 and 28, respectively; and the lower contact members of the switch 41 are connected to the anodes 37 and 38, re-' spectively, of the rectifier 40. The cathodes 42 and 42 of the rectifiers 36 and 40 are connected to a wire 43 leading to the motors of the vehicle, which are arranged in any desired manner, such, for example, as in series multiple. A wire 45 connects the motors to the mid point 46 of the secondary winding 23 of the transformer, 18. The point 47, intermediate in potential between the points 41 and 46, is connected to the ground, preferably through a resistance 48 having a purpose to be hereinafter pointed out.

Having thus described the relative arrangement of the component parts of our system, the operation is as follows: If it is desired to operate the vehicle on one rectifier, as, for example, rectifier 36, the switches 25, 26, 27 and 28 are thrown down, switch 41.is thrown up and switch 32 is thrown to the left. The contact devices 1 and 2 are now closed, whereupon the bus-bars 29 and 31 are supplied with current atthe voltage 2** through the intermediate connections. The rectifier 36 having previously been started by any suitable means, such, for example, as a separate keep-alive circuit, current will flow from the bus-bars 29 and 31 to the anodes 33 and 35, will be rectified, passed through the motors 44 and back to the mid point 46 of the secondary winding 23. In order to accelerate the motors, the contact devices 2 and 3 are closed, whereupon the bus-bar 3O assumes a higher potential than the bus-bar 29, the anode 34 comes into action and the are from the anode 33 is extinguished. The contact device 1 is now opened and the contact device 4 closed, whereupon the bus-bar 29 assumes a potent ial higher than that of the bus-bar 21, the anode 33 again comes into action and the are from th anode 35 is extinguished. This ope 'ation is repeated in the sequence indicated by the numbering of the contact devices until the full voltage of the secondary winding is impressed upon the anodes 33 and 34: through the contact devices 15 and 16. In a similar manner, by throwing switches 26, 27 and 28 down; by throwing the switch %1 up; and by throwing the switch 32 to the right; the entire load may be carried by the rectifier 4:0 and the voltage impressed thereupon varied at will.

It frequently happens that it is desired to operate both rectifiers sinnlltaneously in order that the heat may be more readily distributed. This connection may be readily effected by throwing the switches 25, 26, 27 and 28 up; by throwing the switch 41 down; and by throwing the switch 32 to the left. Under these conditions, if the contact devices 1 and 2 are closed, the bus-bar 29 will assume the potential of the tap 1, and the anode 33 will be energized. Current will flow from the contact device 2 through the left hand blade of the switch 41 to the anode 3S, and the two rectifying devices will operate in a well known manner as single anode rectifiers, necessitating, of course, the use of the aforementioned keep-alive circuits. If now, the contact device 3 is closed, th bus-bar 30 will assume a potential higher than that of the bus-bar Q9 and the anode 3i will come into action, extinguishing the are from the anode The contact device 1 may now be opened with impunity. The contacting device 4: is next closed, whereupon current flows through the right hand blade of the switch 11, the anode 37 comes into action and the are from the anode 38 is extinguished. The closing of the contact device 5 will now raise the voltage of the busbar 29 above that of the bus-bar 39, the anode 33 will come into action and the are from the anode 3% will be extinguished. In this manner, the voltage of the current to be rectified may be raised by steps, in the sequence indicated by the numbering of the contact devices, each rectifier operating as a single anode device, the are being shifted between the anodes 33 and 34: in the rectifier 36 and between the anodes 37 and 38 in the rectifier 40. Under these conditions of multiple operation, the anodes 35 and 39 are at all times inactive.

The voltage between the points 41 and 46 may be of an extremely high value in systems of this character, and it becomes desirable to distribute the voltage strain as much as possible. This result may be attained by connecting the point 417 of intermediate potential to the ground through a resistance 48. By these connections, the voltage strain in none of the motors ever exceeds one-half the voltage between the points etl and 46. Should the wire 43 accidentally become grounded, an excessive current would flow from the fault up through the ground connection and through the right hand motors M, imposing av severe overload upon these motors. The purpose of the resistance 48 is to reduce the flow of a harmful current of this character.

Another type of safety circuit is shown in Fig. 2 wherein the points 1 :7 of intermediate potential are connected to the ground at a point 40 through a fuse 50. The fuse 50 is shunted by a circuit including a resistance element 51 and a solenoid 52. The solenoid 52 controls a contact device 53 which is included in a local circuit comprising a current source 54, a. hand-operated switch 55 and the release coil 56 of an automatic switch 57 inserted in the main supply circuit. The contact device 53 is normally opened and the switches 55 and 57 are normally closed. Upon the failure of the insulation outside of any of the motors, the heavy low of current through the ground circuit at the point 49 will blow the fuse 50, and the coil 52 will be energized. The consequent closing of the contact device 53 will allow current to flow from the source 5% through the coil 56, actuating the automatic switch 57 and opening the main current supply of the vehicle. As a temporary expedient, in order that the vehicle may be taken to the shop the switch 55 may be opened and the switch 57 then closed.

It is obvious that our system is susceptible of many changes which would be included within the scope of our invention and, accordingly, we do not desire to be restricted to the accompanying drawing and description but wish only such limitations to be imposed upon our invention as are indicated in the appended claims.

We claim as our invention:

1. The combination with a source of alternating current, of two, three-anode rectifier units, a plurality of voltage taps on the source, means whereby either of the rectifier units may be connected to the source and operated with two active anodes, means whereby the voltage applied to the active rectifier may be varied by applying the desired voltage to the inactive anode and thereby causing one of the previously active anodes to become inactive, means whereby both rectifiers may be connected to the source and operated as single-anode units, and means whereby the voltage applied to the rectifiers may be varied by applying the desired voltage to an inactive anode in each rectifier and thereby causing the previously active anodes to become inactive.

2. The combination with a source of alternating current, of a transformer winding arranged to be energized therefrom, a mid tap connection and a plurality of voltage taps on each side thereof on said transformer winding, a plurality of multi-anode vapor-converter units, means whereby anyone of said units may be operated as a multianode converter deriving current for a portion of its anodes from taps on one side of said mid tap, deriving current for the remainder of its anodes from taps on the other side of said mid tap and returning current through said mid-tap, and means whereby two of said units maybe operated jointly as single-anode converters, deriving their energy from oppositesides of said mid-tap and returning current therethrough.

3. The combination with a source of alternating current, of a transformer winding arranged to be energized therefrom a midtap connection and a plurality of voltage taps on 'each side thereof on said transformer winding, a plurality of multi-anode vapor converter units, means whereby any one of said units may be operated as a multianode converter deriving current for a portion of its anodes from taps on one side of said mid-tap, deriving current for the re mainder of its anodes from taps on the other side of said mid-tap and returning current through said mid-tap, means whereby two of said units may be operated jointly as single-anode converters, deriving their energy from opposite sides of said mid-tap and returning current therethrough, and means whereby the voltage of the current to be rectified may be adjusted under either system of operation.

4. The combination with a source of alternating current, of a direct-current load subject to variations, a plurality of multianode vapor converting units, and means whereby a portion of said units may be con nected to supply said load from said source by multi-anode operation during light-load conditions, and means whereby a greater number of said units may be connected to supply said load from said source by singleanode operation during heavy-load conditions.

5. The combination with a source of alternating current, of a direct-current load subject to variations, a plurality of multi-anode vapor converting units, and means whereby a portion of said units may be connected to supply said load from said source by multianode operation during light-load conditions, means whereby a greater number of said units may be connected to supply said load from said source by single-anode operation during heavy-load conditions, and means whereby the voltage supplied by said source to said load may be adjusted under either conditions of operation.

6. The method of operating a plurality of vapor converters arranged to supply a variable direct-current load from a source of alternating current which comprises con necting any one of said converters to supply said load by multi-anode operation during light-load conditions and connecting a plurality of said converters to supply said load by single-anode operation during heavyload conditions.

In testimony whereof, we have hereunto subscribed our names this 30th day of June, 1914:.

FRANK CONRAD. KARL A. sIMMoN.

Vitnesses:

G. R. IRWIN, B. B. HINES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 1 

